1. Field of the Invention
This invention is concerned with detergent compositions comprising alcohols and alcohol ethoxylates.
2. Description of the Prior Art
The present invention relates to detergent compositions, in particular to detergent compositions for use in dishwashing machines, such as automatic dishwashing machines.
Dishwashing machines, in particular institutional large dishwashing machines such as canteen and restaurant dishwashing machines, use liquid or powder cleaning agents based mainly on inorganic salts such as inorganic phosphates and strong alkalies. Examples of such phosphates include trisodium phosphate and tetrasodium pyrophosphate and examples of such strong alkalies include sodium carbonate and sodium silicates.
Such liquids or powders usually have one or more of the following disadvantages:
A. they etch glassware and ceramic units, PA1 B. they cause damage of above-glaze decoration on crockery, PA1 C. they often do not prevent formation of deposits of calcium and/or magnesium salts on crockery surfaces, which results in dullness thereof; such salts also cause scaling of machine parts, the removal of which requires a considerable maintenance effort; the tendency towards salt formation often necessitates, in many machines, demineralization of the washing water in order to obtain adequate cleaning performance, and PA1 D. the phosphates, in particular, which are present in the waste water give rise to environmental problems. PA1 a. a C.sub.8 to C.sub.18 alcohol ethoxylate containing, on average, from 2 to 4 moles of ethylene oxide for each mole of C.sub.8 to C.sub.18 alcohol, PA1 b. a C.sub.7 to C.sub.13 alcohol or mixture thereof, PA1 c. a C.sub.1 to C.sub.6 alcohol or mixture thereof, PA1 d. a defoamer, and optionally PA1 e. a C.sub.8 to C.sub.18 alcohol ethoxylate containing, on average, from 5 to 9 moles of ethylene oxide for each mole of C.sub.8 to C.sub.18 alcohol PA1 a. from 60 to 90%w of a C.sub.12 to C.sub.15 alcohol ethoxylate prepared by reacting from 2 to 4 moles of ethylene oxide with 1 mole of a mixture of C.sub.12 to C.sub.15 alcohols, PA1 b. from 10 to 30%w of a mixture of C.sub.9 to C.sub.11 alcohols, PA1 c. from 2 to 9%w of a C.sub.1 to C.sub.6 alcohol, PA1 d. from 0.05 to 2.0%w of a silicone-oil defoamer, and optionally PA1 e. from 10 to 30%w of a C.sub.8 to C.sub.18 alcohol ethoxylate prepared by reacting from 5 to 9 moles of ethylene oxide with 1 mole of a mixture of C.sub.8 to C.sub.18 alcohols, PA1 the percentages being based on total weight of (a), (b), (c) and (d).
The applicants have now discovered liquid non-ionic detergent compositions which are subsubstantially free of inorganic salts and which are based on certain exthoxylated alcohols and certain alcohols, which overcome one or more of the above objections and which are low-foaming and are good cleaning agents. Such non-ionic detergent compositions may in addition also be used in both the wash and rinse cycle of washing machines i.e. they are good rinse and cleaning aids.